Sunscreen formulation
The present application relates to sunscreen formulations, including foamable sunscreen formulations, that comprise zinc oxide and titanium dioxide particles, suitably in the size range of about 1-100 nm. The compositions suitably produce a minimal residual whitening effect when applied to a skin surface.
1 . A foamable formulation consisting of:
a) about 1 wt % to about 25 wt % zinc oxide particles having a primary particle size of greater than about 900 nm;
b) about 0.1 wt % to about 25 wt % skin conditioner;
c) about 0.1 wt % to about 10 wt % suspending agent; and
d) about 0.1 wt % to about 10 wt % emulsifier,
wherein the formulation is an oil-in-water emulsion.
2 . The foamable formulation of claim 1 , wherein the zinc oxide is about 3 wt % to about 20 wt % of the formulation.
3 . The foamable formulation of claim 2 , wherein the zinc oxide is about 5 wt % to about 15 wt % of the formulation.
4 . The foamable formulation of claim 1 , wherein the skin conditioner is selected from an adipate ester, an alkyl benzoate, a fatty acid ester of C 8 or greater, an esterified erucate, a laurate, a neopentanoate, a salicylate, a stearate, a triglyceride, a carbonate, a glycol, glycerin, mineral oil, and a combination thereof.
5 . The foamable formulation of claim 4 , wherein the skin conditioner is selected from a stearate, a triglyceride, a glycol, glycerin, mineral oil, and a combination thereof.
6 . The foamable formulation of claim 5 , wherein the glycol is caprylyl glycol.
7 . The foamable formulation of claim 1 , wherein the skin conditioner is about 1 wt % to about 25 wt % of the formulation.
8 . The foamable formulation of claim 1 , wherein the suspending agent is selected from hydroxy stearic acid, polyhydroxystearic acid, a sodium polyacrylate polymer, a methyl methacrylate crosspolymer, and a combination thereof.
9 . The foamable formulation of claim 8 , wherein the suspending agent is hydroxy stearic acid and/or polyhydroxystearic acid.
10 . The foamable formulation of claim 1 , wherein the suspending agent is about 1 wt % to about 10 wt % of the formulation.
11 . The foamable formulation of claim 1 , wherein the emulsifier is selected from a polysorbate, an ethoxylated fatty acid or salt thereof, a fatty acid neutralized with sodium hydroxide, potassium hydroxide, potassium amine, a substituted glucoside, sodium lauryl sulfate, sodium lauryl ether sulfate, an ethoxylated ester, lecithin or derivative thereof, and a combination thereof.
12 . The foamable formulation of claim 11 , wherein the emulsifier is potassium hydroxide and/or a polysorbate.
13 . The foamable formulation of claim 1 , wherein the emulsifier is about 1 wt % to about 10 wt % of the formulation.
14 . A foamable formulation consisting of:
a) about 1 wt % to about 25 wt % zinc oxide particles having a primary particle size of greater than about 900 nm;
b) a skin conditioner selected from an adipate ester, an alkyl benzoate, a fatty acid ester of C 8 or greater, an esterified erucate, a laurate, a neopentanoate, a salicylate, a stearate, a triglyceride, a carbonate, a glycol, glycerin, mineral oil, and a combination thereof;
c) a suspending agent selected from hydroxy stearic acid, polyhydroxystearic acid, a sodium polyacrylate polymer, a methyl methacrylate crosspolymer, and a combination thereof; and
d) an emulsifier selected from a polysorbate, an ethoxylated fatty acid, a fatty acid neutralized with sodium hydroxide, potassium hydroxide, potassium amine, a substituted glucoside, sodium lauryl sulfate, sodium lauryl ether sulfate, an ethoxylated ester, lecithin or derivative thereof, and a combination thereof,
wherein the formulation is an oil-in-water emulsion.
15 . The foamable formulation of claim 14 , wherein:
the skin conditioner is about 0.1 wt % to about 25 wt % of the formulation;
the suspending agent is about 0.1 wt % to about 10 wt % of the formulation; and
the emulsifier is about 0.1 wt % to about 10 wt % of the formulation.
16 . The foamable formulation of claim 15 , wherein:
the skin conditioner is about 1 wt % to about 25 wt % of the formulation;
the suspending agent is about 1 wt % to about 10 wt % of the formulation; and
the emulsifier is about 1 wt % to about 10 wt % of the formulation.
17 . A foamable formulation consisting of:
a) about 1 wt % to about 25 wt % zinc oxide particles having a primary particle size of greater than about 900 nm;
b) about 0.1 wt % to about 25 wt % skin conditioner;
c) about 0.1 wt % to about 10 wt % suspending agent;
d) about 0.1 wt % to about 10 wt % emulsifier; and
e) about 0.1 wt % to about 10 wt % of an emulsion stabilizer,
wherein the formulation is an oil-in-water emulsion.
18 . The foamable formulation of claim 17 , wherein the emulsion stabilizer is selected from acacia, cellulose, crystalline cellulose, gellan, guar, locust bean, xanthan, magnesium aluminum silicate, bentonite clay, hectorite clay, and a combination thereof.